Diagnostic catheter using a vacuum for tissue positioning

ABSTRACT

A diagnostic catheter and method of use for analyzing tissue is provided. A method for analyzing tissue in accordance with one embodiment of the present invention includes inserting a catheter having a sensor at its distal end into the body of a patient, applying suction through the catheter to secure the tissue to the catheter and then analyzing the tissue with the sensor. An apparatus for analyzing tissue within the body of a patient in accordance with an alternative embodiment of the present invention is also provided. This alternative embodiment includes a catheter having a first end and a second end, the first end having an orifice and a sensor, the catheter also having a lumen.

RELATED APPLICATIONS

[0001] This application is a continuation of U.S. patent applicationSer. No. 09/513,076, which was filed on Feb. 25, 2000, and which isherein incorporated, in its entirety, by reference.

FIELD OF THE INVENTION

[0002] The present invention is directed to the analysis of internaltissue of a patient. More particularly the present invention regards theuse of a vacuum within a patient's body to secure tissue near adiagnostic sensor.

BACKGROUND OF THE INVENTION

[0003] Diagnostic procedures to analyze and diagnose a patient are acommon component of modern medical care. There are numerous diagnosticprocedures that can be performed on a patient. Some of these diagnosticprocedures, such as x-ray and Magnetic Resonance Imaging, are performedcompletely outside of the body while others, such as tissue biopsies andin situ analysis, require entry into the body and more direct contactwith the suspect body part. Those procedures that require more directtissue contact may be performed through the esophagus and other existingorifices in the patient or through incisions, both small and large, madein the body of the patient.

[0004] Whether the diagnostic procedure is performed through an existingorifice or through an incision in the body of the patient, the tissue tobe analyzed may often be out of the direct reach of the practitioner. Inthese situations, in order to reach and analyze the tissue, thepractitioner will often employ an instrument having sensors at itsdistal end. When an instrument is employed the practitioner mustmanipulate and guide the instrument from outside the body in order toposition the sensors, located at its distal end, next to the suspecttissue. This manipulation and steering of the instrument is often atime-consuming and cumbersome process.

[0005] For example, when tissue is analyzed during an endoluminalprocedure, the practitioner must manipulate the medical instrumentcontaining the sensor within the tight quarters of the endoscope. Oncethe sensor is properly positioned by the practitioner, it must then bemaintained adjacent to the tissue in order to receive satisfactoryresults. In some circumstances the practitioner may not be able tosatisfactorily manipulate the sensor in order to position it near thetissue to be analyzed. Similarly they may not be able to satisfactorilymaintain the contact between the tissue and the instrument during theanalysis. To resolve both of these problems, a second instrument, havinga hook at its distal end, has been employed. This second instrument isinserted down into the endoscope in order to hook the tissue, move itnext to the sensor, and hold the tissue in place during the testing. Theapplication of this second instrument, although frequently used, isdisfavored as its use is time consuming and can injure and permanentlydamage the tissue being tested.

[0006] In another example, when diagnostic testing is performed withoutan endoscope, directly through an incision into the patient's body, thepractitioner must also position the sensor adjacent to the suspecttissue and may also be required to hold the tissue in direct contactwith the catheter in order to perform the analysis. Here, too,positioning the catheter and maintaining its direct contact with thetissue is an arduous and tedious process. A second instrument, such asthe hook described above, is often used to grab the tissue, tug it tothe sensor and anchor the tissue in direct contact with the catheter. Asin the endoluminal procedure, the use of this second instrument, thehook, prolongs the procedure and increases the risk of injury to thetissue.

[0007] As is evident, what is needed is a method and an apparatus thatprovides for the diagnosis of suspect and diseased tissue within thebody of a patient without the cumbersome, time-comsuming, and riskyprocedures that have been employed in the past.

SUMMARY OF THE INVENTION

[0008] In accordance with the present invention a diagnostic catheterusing a vacuum for tissue positioning is provided. A method foranalyzing tissue in accordance with one embodiment of the presentinvention includes inserting a catheter having a sensor at its distalend into the body of a patient, applying suction through the catheter tosecure the tissue to the catheter and then analyzing the tissue with thesensor.

[0009] An apparatus for analyzing tissue within the body of a patient inaccordance with an alternative embodiment of the present invention isalso provided. This alternative embodiment includes a catheter having afirst end and a second end, the first end having an orifice and asensor, the catheter also having a lumen.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]FIG. 1 is a catheter in accordance with a first embodiment of thepresent invention.

[0011]FIG. 2 is a cross-sectional view along line 2-2 of FIG. 1.

[0012]FIG. 3 is an enlarged view of the catheter from FIG. 1 after beingplaced next to tissue to be analyzed.

[0013]FIG. 4 is an enlarged view of the catheter from FIG. 1 wherein avacuum force has been used to draw tissue down and in contact with thecatheter.

[0014]FIG. 5 is the distal end of an endoscope containing a catheter inaccordance with a second embodiment of the present invention.

[0015]FIG. 6 is a catheter employing a syringe to create a vacuum forcein accordance with a third embodiment of the present invention.

[0016]FIG. 7 is a cross-sectional view of the distal end of a catheterin accordance with a fourth embodiment of the present invention.

DETAILED DESCRIPTION

[0017]FIG. 1 illustrates a catheter 10 in accordance with a firstembodiment of the present invention. This catheter 10, which may betube-shaped and may have a 2-3 mm external diameter, contains a hollowcylindrical distal tip 120 as well as a hollow cylindrical catheter body190 and a hollow cylindrical tube 185. The distal tip 120 contains fourequally sized orifices 100 along its surface. These orifices 100, whichmay be 0.5 mm in diameter, penetrate completely through one of the wallsof the catheter's 10 hollow cylindrical distal tip 120 and may be spaceda diameter apart from one another. The hollow cylindrical distal tip 120also contains three sensors 110 affixed to its surface and equallylocated between the four orifices 100. These sensors 110 may be numeroustypes of sensors including electrical sensors that test the voltage dropacross the tissue being tested, ultrasound sensors, such as the BostonScientific/SCIMED UltraCross® TX200 transducers, which employ soundwaves to analyze the tissue, and optical sensors, which employ visibleor non visible light to sense the properties of the tissue beinganalyzed. These sensors 110 are connected to sensor line 195 which islocated within the distal tip 120, the catheter body 190, and thecoupler 180. This sensor line 195 connects the sensors 110 with thesensor communication cable 130. The sensor communication cable 130 is inturn connected to a sensor output device (not shown) such as a cathoderay tube. Dependent upon the type of sensors 110 employed the sensorline 195 and the sensor communication cable 130 may be electrical wires,optical fibers, or some other communication link.

[0018] As can be seen, a vacuum hose 160 is also connected to thecoupler 180. In addition to being connected to the coupler 180 on oneend, the vacuum hose 160 is also connected to a vacuum pump, which isnot shown, at the other end. This vacuum pump, although not illustrated,may be a 1180 Gomco suction unit, capable of creating a vacuum between 0and 22 in. Hg and having a bottle coupled to it to prevent solids andliquids from entering the pump. This vacuum pump is used to create aninward suction force through the orifices 100 located at the distal tip120 of the catheter 10. This inward vacuum force generated by the vacuumtravels from the vacuum pump through the vacuum hose 160, through thefirst vacuum channel 165 located in the coupler 180 and the tube 185,through the suction adjustment valve 175, back through the tube 185,this time in the second vacuum channel 155, which is located within thetube 185, through the coupler 180, the catheter body 190, and the distaltip 120, such that the vacuum force is in fluid communication with theorifices 100.

[0019] A suction adjustment knob 170 is rotationally connected to thesuction adjustment valve 175. This suction adjustment valve 175regulates the amount of suction from the vacuum pump (not shown) thatwill be transferred from the first vacuum channel 165 to the secondvacuum channel 155 and eventually to the orifices 100 located in thedistal tip 120 of the catheter 10. By turning the suction adjustmentknob 170 the suction adjustment valve 175 is opened or closed and theamount of suction drawn through the orifices 100 at the distal tip 120of the catheter 10 is either concomitantly increased or decreased.

[0020] In practice a practitioner utilizing the catheter 10 of FIG. 1may insert the catheter 10 into the body of the patient through anexisting orifice or through an incision made specifically for theprocedure. The practitioner would then position the distal tip 120 ofthe catheter 10, which is made from a flexible polymer, allowing thepractitioner to bend and flex the catheter next to the tissue to bediagnosed. Then, once the catheter's 10 distal tip 120 is in its desiredposition, the practitioner would then turn the vacuum pump on and adjustthe amount of vacuum that will be drawn through the orifices 100 at thedistal tip 120 of the catheter 10 by turning the suction adjustment knob170. As the practitioner rotates the suction adjustment knob 170 andincreases the vacuum drawn through the four orifices 100, the tissue tobe analyzed is drawn towards the orifices 100 and, consequently, towardsthe sensors 110. Once the suspect tissue has been repositioned and comesin contact with the sensors 110 the strength of the vacuum force may bemaintained or it may be reduced by the practitioner to a levelsufficient to maintain the contact between the tissue and the sensors110. By reducing the vacuum force holding the tissue to the sensors 110the concentrated forces on the tissues are reduced. The distal tip 120of the catheter 10 and the sensors 110 will remain in contact with thetissue for the duration of the analysis.

[0021] Once the requisite analysis and diagnosis has been completed thevacuum may be reduced by turning the suction adjustment knob 170 or byturning the vacuum off, and the tissue will be free to revert back toits original resting position within the body. Once the tissue isreleased from the orifices 100 the catheter 10 can be removed from thepatient or the procedure can be repeated again, as many times asrequired, for different sections of tissue.

[0022]FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1.As can be seen the distal tip 120 of the catheter 10 has a circularcross-section and the orifice 100 penetrates through the surface and theinner wall 200 of the distal tip 120. The sensor line 195 as well as thesecond vacuum channel 155 are also evident in FIG. 2.

[0023]FIG. 3 is an enlarged view of the distal tip 120 of the catheter10 after it has been positioned near a tissue 330 within the body of thepatient. Inward force arrows 320 are clearly shown. The inward forcearrows 320 highlight the position of the downward force created throughthe plurality of orifices 100 by the vacuum being drawn through thesecond vacuum channel 155. The direction of the vacuum forcecommunicated from the vacuum pump through the catheter to the secondvacuum channel 155 is illustrated by arrow 360.

[0024] In practice, and as discussed above, as the amount of vacuum isincreased the tissue 330 is drawn down to the orifices 100 until thetissue 330 meets the sensors 110. The sensors 110, now touching thetissue, analyze the tissue and output their results to sensorelectronics, including the cathode ray tube discussed above. Once therequisite data is obtained the vacuum is reduced, the tissue 330 isreleased, and the catheter may be removed or the procedure can berepeated again on a different area of tissue.

[0025]FIG. 4 illustrates the distal tip 120 of the catheter after thesuction being drawn down the second vacuum channel 155 has beenincreased, as shown by arrow 400, the suction now drawing the tissue 330down and in contact with the sensors 110. The contact points between thesensors 110 and the tissue 330 are highlighted by arrows 410.

[0026]FIG. 5 illustrates the distal end 595 of a second embodiment ofthe present invention wherein a catheter 565 is inserted into theinternal working channel 570 of an endoscope 510. As can be seen, alight tip 520 of a light pipe 580 is located at the distal end 595 ofthe endoscope 510. This light tip 520 is connected the light pipe 580which is connected to a light source located at the proximate end of theendoscope (not shown). Also located at the distal end 595 of theendoscope 510 is an optical sensor 530. The optical sensor 530 isconnected to a communication line 590 which links the optical sensor 530to the proximate end of the endoscope 510 (not shown) and allows theimages gathered by the optical sensor 530 to be viewed by thepractitioner on a nearby display screen. This optical sensor 530 may beused to assist the practitioner in navigating the distal end 595 of theendoscope 510 to the tissue to be analyzed or alternatively it may beutilized to inspect tissue being analyzed by the sensors 550 located onthe distal tip 560 of the catheter 565.

[0027] As is evident, the catheter 565 is located within the internalworking channel 570 of the endoscope 510. The distal tip 560 of thecatheter 565 extends from the distal end 595 of the endoscope 510 inthis illustration. As in the previous embodiments, the distal tip 560contains several orifices 540, three in this embodiment, as compared tothe four orifices utilized in the embodiment described above. The distaltip 560 also contains two sensors 550 as compared to the three employedin the first embodiment.

[0028] A practitioner using this second embodiment would first insertthe catheter 565 into the internal working channel 570 at the proximateend (not shown) of the endoscope 510. The catheter 565 would onlypartially be inserted into the internal working channel of the endoscope510 such that the distal tip 560 of the catheter 565 would not emergefrom the distal end of the endoscope 510 at the beginning of theprocedure. Next, the endoscope 510 may be inserted into the body of thepatient through an opening, such as the mouth, or through an incisionmade in the body specifically to accommodate the diagnostic procedure.The endoscope 510 would then be guided into position from outside thebody of the patient by the practitioner. If necessary the practitionermay turn the light tip 520 on and use the optical sensor 530 to assistin guiding the distal end 595 of the endoscope 510 down into its desiredresting location. Then, once the distal end 595 of the endoscope 510 waspositioned near the tissue to be analyzed the practitioner would extendthe catheter's 565 distal tip 560 out from inside the internal workingchannel 570. The practitioner would then position the distal tip 560 tobe adjacent to the tissue to be analyzed, the orifices 540, located onthe distal tip 560, facing the tissue to be tested. Similar to thepositioning of the endoscope, the practitioner may also illuminate thelight tip 520 and utilize the optical sensor 530 to aid in properlypositioning the distal tip 560 of the catheter 565. Once the distal tip560 of the catheter 565 is properly positioned, the practitioner wouldturn on the vacuum source in order to draw the tissue towards theorifices 540. Once the sensors 550 began to adequately sense the tissue,the practitioner could then adjust the vacuum being drawn through theorifices, either at the source of the vacuum or at the catheter 565through an adjustment valve (illustrated above), so that only therequisite amount of force was utilized to maintain contact between thesensors 550 and the tissue being analyzed.

[0029] Now coupled to the distal tip 560 of the catheter, the tissue, inaddition to being analyzed by the sensors 550, may also be manipulatedby the practitioner by moving the catheter at its proximate end (notshown). As required, the tissue may be manipulated within the view ofthe optical sensor 530. Once the required data was obtained by thesensors 550, the vacuum would be reduced until the tissue would bereleased from the orifices 540. If additional tissue testing wasrequired, the procedure would be repeated. Once the requisite testingwas completed the distal tip 560 of the catheter 565 would be withdrawnback into the endoscope 510 so that it no longer extended outside of theendoscope 510. The endoscope 510 would then be removed from the body.

[0030] While a light 520 and an optical sensor 530 are shown at the endof the endoscope 510 other diagnostic components can also be placed atthe end of the endoscope 510 to assist the practitioner. For example,the same electrical and ultrasonic sensors placed on the surface of thedistal tip 560 of the catheter may also be placed on the distal end 595of the endoscope 510 to provide additional sources of data to thepractitioner during the diagnosis.

[0031]FIG. 6 illustrates a catheter 60 in accordance with a thirdembodiment of the present invention. In FIG. 6 the catheter 60 has acatheter body 690 containing a sensor line 695. The catheter body 690 isrigidly connected to a coupler 680. The coupler 680 has a sensorcommunication cable 630 and a vacuum hose 660 protruding from thecoupler's 680 lower side. The vacuum hose 660 has a connection hose 625sealably connected to the vacuum hose 660. The connection hose 625 issized to fit to the connection hose 625 on one side and to a syringe 615on the other. The syringe 615 is in fluid communication with theorifices 630 via the connection hose 625, the vacuum hose 660, thecoupler 680, and the catheter body 690. The syringe 615 contains aplunger 605. When the plunger 605 is drawn out, in the direction of thearrow, it creates a vacuum force that is ultimately transferred to theorifices 600 at the distal tip 620 of the catheter 60. This syringe 615is, therefore, an alternative to the vacuum pump described in theprevious embodiments. When the syringe 615 is used, the vacuumadjustment valve 675 would be rotated until it was completely open sothat the practitioner would be controlling the amount of vacuum forcegenerated at the orifices 600 of the catheter 60 by sliding and holdingthe plunger 605 of the syringe 615.

[0032] Alternatively, as illustrated in FIG. 7, which is across-sectional view through the distal end of a fourth embodiment ofthe present invention, the sensors 710 and the orifices 700 do not needto be in line with one another along the outside surface of thecatheter. Instead, they may also be placed at different locations of thedistal tip 720 of the catheter. For example, as is evident in FIG. 7 theorifice 700 penetrates through the top of the outside surface of thedistal tip 720 of the catheter while the sensor 710 is positioned alonga side of the outside surface of the distal tip 720 of the catheter.Similarly, while the sensors are illustrated on the surface of thecatheter they may instead be formed in the catheter or placed on theinside wall 755 of the distal tip 720 of the catheter. Also, while anendoscope is described in the embodiments above, a flexible tubecreating a pathway may, instead, be used in its place. Therefore, aswill be evident to one of skill in the art, the above embodiments aremerely illustrative of the invention disclosed herein and otherembodiments may be employed without departing from the spirit and scopeof the present invention.

What is claimed is:
 1. A method of analyzing tissue within the body of apatient comprising: inserting a catheter into the body of a patient, thecatheter having a sensor at a distal end and an orifice through andflush with an external peripheral surface of the catheter, the orificebeing proximate to the sensor, applying a vacuum force through theorifice to secure a portion of tissue to be analyzed flush with anexternal peripheral surface of the catheter and adjacent to the sensor;and analyzing the tissue with the sensor.
 2. The method of claim 1wherein the catheter inserted into the body is carried within anendoscope having a distal end.
 3. The method of claim 2 wherein thedistal end of the endoscope contains at least a light or an opticalsensor.
 4. The method of claim 3 further comprising: manipulating thecatheter to move the tissue towards the distal end of the endoscope, andviewing the tissue utilizing the optical sensor.
 5. The method of claim1 further comprising: reducing the vacuum force applied through theorifice while maintaining the tissue flush with the external peripheralsurface of the catheter.
 6. The method of claim 1 wherein the sensor isan ultrasound transducer.
 7. The method of claim 3 wherein the opticalsensor is an infrared sensor.
 8. The method of claim 4 wherein theoptical sensor is an infrared sensor.
 9. A method of analyzing tissuewithin the body of a patient comprising: extending a catheter having asensor from the distal end of an endoscope to a position adjacent to apreselected tissue to be analyzed; positioning an orifice of thecatheter adjacent to the preselected tissue to be analyzed, the orificeof the catheter flush with an external peripheral surface of thecatheter; and, applying a force to the tissue via the catheter to securethe tissue into a predetermined sensing position relative to the sensor,wherein at least a portion of the tissue is positioned flush with theexternal peripheral surface of the catheter and adjacent the sensor; andanalyzing the tissue with a sensor supported by the catheter.
 10. Themethod of claim 9 wherein the force is applied to the tissue with anegative pressure created through the orifice of the catheter.
 11. Themethod of claim 10 further comprising: illuminating the tissue securedto the catheter with a light located on the endoscope; and viewing thetissue with an optical sensor located on the endoscope.
 12. A method ofanalyzing tissue within the body of a patient comprising: positioningthe distal end of an endoscope to a predetermined position adjacent totissue to be tested; extending a catheter, located within the endoscope,out of the distal end of the endoscope and positioning the catheter in apredetermined position; applying suction through an orifice locatedthrough and flush with an external peripheral surface of the catheterand proximate to a sensor to secure a portion of the tissue flush withthe external peripheral surface of the catheter and adjacent a sensor;and analyzing the tissue with the sensor located on the catheter. 13.The method of claim 12 wherein the sensor is an infrared sensor.
 14. Anapparatus for analyzing tissue within the body of a patient comprising acatheter having a first end, a second end, and an outer surface, thefirst end having an orifice through a side surface of the catheter, thefirst end also having a first sensor on a side surface, the first sensorpositioned on the catheter to sense tissue secured to the orifice, theorifice defining a recess into the catheter, the recess extending intothe catheter, the recess having an outer edge, the outer edge of therecess being flush with the outer surface of the catheter; an endoscopesurrounding the catheter; and, a vacuum channel in fluid communicationwith the orifice.
 15. The apparatus of claim 14 further comprising asuction adjustment valve in fluid communication with the vacuum channel.16. The apparatus of claim 15 further comprising: a light located on adistal end of the endoscope.
 17. The apparatus of claim 14 wherein thefirst sensor is an electrical sensor.
 18. The apparatus of claim 14further comprising: a second orifice through a side surface of thecatheter, the sensor positioned between the first orifice and the secondorifice.
 19. The apparatus of claim 18 further comprising: a secondsensor, the first sensor and the second sensor located on a side surfaceof the catheter, the first sensor and the second sensor having anorifice between them.
 20. The apparatus of claim 19 further comprising:a sensor line in communication with either the first sensor or thesecond sensor, the sensor line molded into the side of the catheter. 21.A device for analyzing tissue within the body comprising: a catheterhaving a first end, a second end, an outer surface,/and a lumen, thefirst end having an orifice through a side surface of the catheter, thefirst end also having a first sensor on a side surface, the first sensorpositioned on the catheter to sense tissue secured to the orifice, theorifice defining a recess into the catheter, the recess extending intothe catheter, the recess having an outer edge, the outer edge of therecess being flush with the outer surface of the catheter.
 22. Thedevice of claim 21 wherein the catheter contains a plurality of orificesand a plurality of sensors.